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Code Green

Cracking the Code

The IRC will most likely be the building code you will use for your next green building project.
Image Credit: International Code Council

It’s complex and hard to read… That’s why they call it a Code!

If you’re going to build green or otherwise, you’ll need to crack the code. The process begins with a permit and you’ll pass a series of inspections. Here’s a primer of the code, but it’s worth getting a copy
to read as well.

The International Residential Code (IRC) is more than likely the code that will regulate the work to build a green home, an addition or even remodeling project. It is adopted in some fashion in 48 states. Verify your community’s code here.

The IRC is a comprehensive design and construction document

This stand-alone document includes all aspects of construction including architectural, structural, energy, plumbing, mechanical and electrical installations. It is published by the International Code Council (ICC), a non-profit organization that includes City and County Building Officials, Builders, Architects, Engineers, Firefighters, Plumbers and Mechanical Contractors and similar professionals across the country. This group follows a systematic process for continual improvement that results in a new published code book every three years (2006, 2009, 2012, etc).

This code is divided into nine parts (I–IX). Each part may have several chapters lumping all requirements that are correlated together. Here’s a brief rundown of the parts and their chapters:

I. Administration

Duties and powers of the Building Official, permit requirements, construction documents, fees, inspections, certificates of occupancy and violations. Most jurisdictions (States, Counties and Cities) will delete this chapter in favor of one written by them.

II. Definitions

Because a code has the force of law, misinterpretations in word definitions can be costly in many ways. One example is the story limit of a building: the definition is based on height of building, grade plane, grade as well as story height. These definitions narrowly define a condition where a structure with four levels (3 stories and a basement) can still be regulated with the IRC when the initial scope says it is limited to three stories…above grade.

III. Building planning

Chapters 4-10 cover foundation design, floor, wall, and roof construction, exterior and interior siding, roofing, chimneys and fireplaces. Within each chapter, only a few material types are referenced with their minimum design standards. But the code does not limit your choices to only these materials. Section 104.11 allows substitutions, and in subsequent articles, I will expand on this subject. For now, just know that the option exists and the intent of the code is not to exclude any new innovation of alternative construction material of method of building.

IV. Energy conservation

Chapter 11 offers you one of two approaches to meet the minimum standards: you can either meet the requirements of the International Energy Conservation Code or meet the requirements of this chapter. The choices are prescriptive and performance — see “When You Come to a Fork in the Code, Take It”

V. Mechanical installations

Chapters 12-23 cover HVAC equipment, ducts, vents and exhaust. These chapters regulate the safety of heating, cooling and conditioning of air in your home.

VI. Fuel gas appliances such as natural gas appliances.

VII. Plumbing

Chapters 25-32 cover drain, waste and vent piping as well as water supply. Typical regulations include quality and size of pipe, water temperature and pressure, cross connection control and water heaters.

VIII. Electrical

Chapters 33-42 covers electrical installations such as service size and type, wire type and overcurrent devices (Circuit breakers), grounding and bonding.

Each of these chapters delineates the minimum requirements for these various utility installations.

IX. Standards

Standards are different from code. Standards generally establish the baseline for material quality or installation methods whereas codes establish the minimum installation conditions for those same materials or products. It’s basically, minimum standards of practice that as a professional, you should do vs. the law. If you don’t follow the standards of practice, you’re negligent, but you’re not breaking the law unless the code specifies compliance as a requirement.

The National Concrete Masonry Association (NCMA) has developed a standard for the Design and Construction of Plain and Reinforced Concrete Masonry and Basement and Foundation Walls with the identification number of TR 68-A—75.

Concrete and masonry foundation walls shall be selected and constructed in accordance with the provisions of Section R404 or in accordance with ACI 318, ACI 332, NCMA TR68–A or ACI 530/ASCE 5/TMS 402 or other approved structural standards.

Section R404.1

Notice that the code uses standards that include several standard developing organizations, including NCMA. This allows the builder to shop for a material that complies with at least one of these standards. So the code sets one or more standards as the baseline for material quality or installation conditions.

The rest of the IRC is appendices with optional methods that are used in rare instances such as gas piping, venting, gas appliance inspection, manufactured housing, radon mitigation, swimming pools, patio covers, private sewage disposal (septic tanks), existing buildings, sound transmission, permit fees, home day care, plumbing venting alternatives, gray water systems, and residential sprinkler standards.

Normally, when a code is adopted, the appendices must be specifically referenced in the adoption process or they do not have the force of law. These provisions are in an appendix chapter instead of the body of the code because a jurisdiction would typically would need to decide if any particular installation was appropriate for their community or not.


How does the IRC relate to you as a Green Builder?

You may be reading this because you’re concerned about how the code will limit your ability to build green. Please put those fears aside. The code development community is keenly aware of your concerns and is making huge strides toward helping you build green. go to and notice the plethora of focus on Green Building.

ICC is leading the way on green building, and building officials nationwide are hearing your message. In the past few years, ICC has worked together with the National Association of Home Builders and several other stakeholders to develop the first ANSI-accredited green-home building standard
, the ICC 700. ICC continues to embrace green initiatives, and more and more of that language is moving into the code. For example, the use of gray water systems or insulated concrete forms (ICFs) is now a prescriptive option for builders.

In future blog postings, I will address the use of alternative materials and methods of construction, modifications to the building code, and how to talk to your inspector to increase your understanding of the regulatory world.


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